$ { \left[\begin{array}{rr}{2} & {-2} \\ {1} & {-2} \\ {2} & {3}\end{array}\right]+\left[\begin{array}{rr}{1} & {1} \\ {-2} & {-1} \\ {3} & {0}\end{array}\right] = {?} } $
To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{2}+{1} & {-2}+{1} \\ {1}+{-2} & {-2}+{-1} \\ {2}+{3} & {3}+{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{3} & {-1} \\ {-1} & {-3} \\ {5} & {3}\end{array}\right]}$